William edgar peall



(No Model.)

W. E. PRALL; JI.

\ STEAM MOTOR FOR STREET GARS.

No. 393,263. Patented Nov. 20, 1888.

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UNITED STATES PATENT WILLIAM EDGAR PRALL, J R. OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO YVILLIAM E. PRALL, OF SAME PLACE.

STEAM-=IVIOTOR FOR STREET-CARS.

EPECIFICATION forming part. of Letters Patent No. 393,263, dated November 20, 1888.

Application filed May 16, 1688, Serial No. 273,958. (No model.)

To aZZ whom it may concern.-

Be it known that 1, WILLIAM EDGAR PBALL, J r. a citizen of the United States, residing at Washington, District of Columbia, have invented certain new and useful Improvements in Steam-Motors forStreet-Cars; andIdo declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to the letters and figures of reference marked thereon,

which form a part of this specification.

The object of the invention is to provide means adapted to move by the aid of steampower ordinary street-cars-such as are usually drawn by horsesand to provide for this purpose an apparatus that can be safely and readily managed by persons of ordinary intelligence, and in which the generation of steam can be instantaneously begun or stopped at will by simply manipulating a lever, and in which all danger of excessive pressure is avoided and also all disagreeable odors, vapors, and noise.

The invention consists in certain devices and combinations, hereinafter described and pointed out.

In the accompanying drawing, which forms part of this specification, the figure represents a side view, partly in section, of a car and of my improved apparatus applied thereto, and 1 indicates a hot-water reservoir; 2, a gasolinetank; 3, a device for vaporizing the oil by means of hot water; 4, a steam-generator, and 5 a steam-cyliuder having connection to drive the car.

The hot-water tank communicates with a smaller tank or receptacle, 6, by means of a pipe, 7, having a cock or valve, 8, and said smaller tank communicates with the steamgenerator by means of a pipe, 9, havinga needie or pressure-reducing valve, indicated at 10. The oil-tank communicates with what may be styled a cooling-tank, 11, by means of pipe 12, which may be provided with a stopcock. Pipe 12 communicates with the coolug-tank and extends into the interior of the small hot-water receptacle 6,where it is formed into a coil of zigzag or equivalent form, and it is continued to and communicates with an annular chamber, 13, which surrounds receptacle 6. A bent pipe, 14, connects chamber 13 with a mercury seal, 15, or equivalent, as indicated. The space above the mercury is connected by means of pipe 17 with the head or cross tube 18, from which extend the burnertubes 19, provided with burner-outlets, as indicatcd.

20 indicates a valve or cook for stopping the flow of gasoline-vapor in pipe 17, and 21 a small by-pass pipe, the object of which is to supply gasoline-vapor or other fuel to a lighting-burner consisting of burner-tubes having comparatively small openings arranged adjacent to the main burner-openings.

16 is a vapor or gas pipe to supply lightingburners, as shown.

22 indicates a coil of pipe, preferably made of copper, about three-fourths of an inch in diameter, which communicates with pipe 9, and, through said pipe and receptacle 6 and pipe 7, with tank 1. There is preferably ar: ranged under each of several sections of said pipe an asbestus shield, which serves the double purpose of protecting the pipe from the direct action ofthe flame and of compelling a tortuous circulation of the products of combustion to bring them in repeated contact with the coil.

23 is a pipe forming an extension of the steam-generating coil and arranged to convey steam to the steam-chest of the cylinder. This pipe is provided with a Valve or cook, 24.

The cock 8 in the hot-water pipe, the cook 20 in the'vapor-pipe, and the cock 24E in the steam-pipe are all opened or closed simultaneously by rod 25, having lever-handle 26 conveniently located, as on the platform of the car. connected with the axle or wheels of the car in any approved manner. Sprocket wheels and chains are indicated in the drawing.

The water-tank 1 may be made to hold thirty or forty gallons of water under a pressure of about three hundred pounds and at a temperature of about 400 Fahrenheit. It can be filled through the stop-cock 29. It is preferably provided with a non-conducting jacket of asbestus or other material to check radiation, as also are receptacles 13 and 6 and the various connecting-pipes. Tank 1 communicates by The piston-rod of the steanrcylinder is I these several tanks and receptacles are not material. The object of the mercury seal is to effectually preclude the possibility of the fiame running back from the burner and igniting-vapor in vapor-chamber 13.

The steam-generating coil may have a total pipe-length of four hundred feet or more. It is preferred to construct this generator in tubular sections, so styled, as commonly practiced in steam boilers and radiators. According to this method two or more tubes ar ranged side by side are connected at both ends to hollow couplings so constructed that each tube communicates with the interior of the coupling and with the other tubes. Steam entering a coupling passes into each of the tubes, and through them to an opposite coupling, which latter communicates with a similar coupling of another like section, all as will be readily understood by those acquainted with steam-boilers. Instead of a coil as described, a steam-generator of any approved form may be employed without sacrificing the benefits of other parts of the improvement.

In practice two, three,or four inch steam cylinders, connected each to a wheel on the axle and adapted to work under a pressure of from one hundred to one hundred and fifty pounds are preferred. The exhaust-steam is conducted through pipes 30 to the top of the car and discharged through an air -injeetor, a preferred form of which is indicated at 31. To obviate noise, the steam may be passed out through wire-gauze diaphragms arranged in this injector, or through numerous openings in any approved manner, and the drip can be conducted to the ground by asuitably-arrauged pipe. Pipe 30 may be provided with an extension running around or through the car, preferably near the floor, to heat the same in cold weather, said extension being provided with a valve near the main vertical pipe 30, so that it can be cut off when the healing of the car is not desirable.

Air is admitted to the burners either by receiving it through ventilating-pipes from the ear or from the open air. In the latter case a wire-gauze or perforated plate can be located beneath the burners to distribute and modify the air-currents. The products of combustion escape through the chimney, as indicated.

closed, doors or openings being provided for ready inspection or for facilitating repairs.

The operation of the apparatus is as follows:

The tank 11 is filled with a vaporizable fuel, preferably gasoline, a reserve being held in tank 2, and tank 1 is filled at stop-cock 29 with water heated to a temperature of 400 Fah renheit. The several cocks 8, 20, and 24 being opened by lever 26, hot Water flows through pipe 7 into the gasoline-heating receptacle 6 and speedily raises the temperature of the gasoline in pipe 12 above the point of vaporization. The vapor passes through the charm ber 13 and dip-pipe 14, and through the mercury in theseal into pipe l7,and thence through the main or cross pipe 18 to its burner-tube branches and is there ignited. In the meantime the hot water passes through receptacle 6 and pipe 9, and through the needle-valve opening in the latter into the copper coil, where it is instantaneously converted into highlyheated steam with pressure suflicient to drive the car by means of the cylinders and their connections. hen desired, the steanr cock 2 1, the vapor-cock 20, and the watercock can be closed by lever 26 shutting off steam from the cylinders, vapor from the burners, and water from heating-receptacle 6, thus obviating dangerous increase of press ure in the generator. The steam in the generator is normally expanded andhi ghl y heated, and said generator contains no water, as it only receives momentarily the small quantity that is forced in through the needle-valve open ing by pressure from the hot-water tank and which is at once made into steam. To render the apparatus doubly secure, however, the valve at 28 is set to open at any desired degree of pressure greater than that in tank 1, whereby excessive steam-pressure in the generator would be relieved.

The closing of vapor-cock 20 does not shut off the supply from either the lighting devices in the car or from the igniting-burner. To begin the generation of steam it is only necessary to open the several cocks by means of lever 26, whereupon water is immediately forced into the coil and vapor supplied to the burner and ignited by the small permanent flame of the igniting-burner.

Should the hot water admitted to receptacle 6 volatilize more gasoline than required at any time, it will raise the pressure in the coil and force the fluid in the pipe back into the cooling-tank 11, where it will be condensed.

As represented, the receptacle 6 is surrounded by an annular vapor-chamber, 13. The latter might, however, be omitted in some cases without departing from the invention, as the vapor-pipe itself could be made of suflieient size and length to contain a reserve of vapor.

An oil-burner of known construction could be substituted for the burner described without sacrificing the advantages of the improvement, in which case the vaporizing-tank 6 ci's.

would not be used and cook 20 would be placed in the oil-supply pipe and be operated to out off the fuel-supply. Thus the gasoline or fuelsupply pipe 31 might be provided with a valve and operated by an extension of rod 25,(shown in dotted lines,) said pipe being continued direct to cross-pipe 18, supplying suitable burn- By providing cocks 32 and 33 the apparatus would be adapted to supply either oil or vapor to the burners.

From the foregoing it will be seen that the pressure of both gasoline-vapor and steam is automatically relieved, the former by the action of an excess of pressurein tank 6 and coil 12, whereby the oil is forced back and out of such coil and into the cooling-tank 11 and its supply-pipe, and the latter by means of reliefvalve 28; that the supply of fuel, the supply of steam, and the generation of the latter can be instantly stopped or started; that the fire can be instantly quenched or kindled; that no water is held in the generator; that no ashes are thrown upon the street and no steam into the air, and that every operation except that of filling the tanks at the station can be controlled by a person of ordinary intelligence by means of the single operating-lever. The invention, however, is not limited to a single operating-lever, as other mechanical powers might be substituted, and also a separate lever or other instrumentality might be used for each valve. These operating devices can conveniently be duplicated in such manner that they may be controlled from either platform, as desired-as, for example, by extending rod 25 to both platforms and providing it with a lever at each end.

It is obvious that the herein-described improvements do not relate to the particular car, but are applicable generally to vehicles usinga steau1-motor; and further,thatneithertheuse of mercuryinstead ofothersuitable sealing-liquid, nor the particular location of form of the condenser, oittank, and hotwater reservoir, nor the particular form of valves, steamgenerating coil,and steam-cylinder are ofthe essence ofmy invention, which includes these elements in the form and manner shown and all wellknown equivalents for every part herein set forth acting in substantially the same way to produce like results.

Heretofore in steam generators using a liquid fuel devices for regulating and cutting off the supply of water and fuel have been arranged to act simultaneously through connected mechanism, and such matters are not herein claimed. In my apparatus connected mechanism is employed which simultaneously closes a valve or equivalent in the water-pipe, fuel-pipe, and also in the steam-pipe between the generator and the steanrcylinder.

Having thus described my invention, whatI claim, and desire to secure by Letters Patent, 1s-

1. The combination of the hot-water-storage tank, a pipe connecting it with the steaur generator provided with a pressure-reducing valve, a fuelsupply pipe provided with a valve, the burner, and the steanrgenerat-or, substantially as set forth, whereby water may be forced by the pressure of the storage-tank into the generator and instantaneously converted into steam, and whereby fuel for the heatingburner may be instantly cut off.

2. The combination of the hot-watcr-storage tank, a pipe connecting it with the steamgenerator provided with a pressure-reducing valve, a fuel-supply pipe provided with a valve, the burner, the steanrgenerator, and an igniting-lmrner, substantially as set forth, whereby water may be forced by the pressure of the storage-tank into the generator and instantaneously converted into steam, and whereby fuel for the heating-burner may be instantly cut off, and whereby also the fuel may be immediately ignited upon the opening of the valve in the supply-pipe.

3. In an apparatus for propelling cars, the combination of the oil and water tanks, the vaporizing and cooling receptacles, the steamgenerator and burner, and pipes connecting the water-tank with the vaporizing-tank and the latter with the generating-coil, pipes extending from the oil-tank through the vaporizing water-receptacle to the burner, and a needle-valve in the water-pipe between the generator and the vaporizirig-receptacle, sub stantially as specified.

4. The combination of vaporizing-receptacle,vapor-pipe, mercury seal, and burner with a water-pipe having a needle-valve and a steam-generating coil, substantially as specified.

5. The combination of the water supply pipe and its valve, the fuel-supply pipe and its valve, the burner, the steam-generator and steam-pipe having a valve, the several valves being connected to one operating mechanism, whereby the valves can be simultaneously opened or closed, substantially as specified.

6. The combination of the hot-water-supply pipe and its valve, the hot-water receptacle, the fuel-supply pipe and its valve, the burner, and the steam generator and cylinder, the several valves being connected to one operating mechanism, whereby the valves can be simultaneously opened or closed, substantially as specified.

7. The combination of a water-supply pipe having a needle-valve with asteam-generator and steam-pipe, a vapor-pipe, and mercury seal, a burner and valves operated by a single lever to close both the steam and vapor pipes, substantially as specified.

S. The combination of the water-tank, the water supply pipe with needlevalve, the steam generator and pipe, pipe 27, having a pressure-valve opening toward the tank, a vaporpipc and burner, and valves in the vapor and steam pipes, substantially as specified, whereby, when the valves are closed, the fuelsupply is cut ed and means are provided for relieving any accidental excess of pressure in the generator.

9. In a street-car, the combination of the steam generator and pipe, vapor bnrner, and vapor-supply pipe, both pipes having valves operated by a single lever, the steam-cylinder, the exhanst'steam pipe, and the condenser for exhaust-steam, substantially as specified.

10.- The combination of the vaporpipe having a branch connected with an illuminatinghurner, a branch connecting with a lightingburner, the main vapor-burner, the steamgenerator, the valves in the vapor and steam pipes, the vapor-pipe valve being located between the branches of the vaporpipe and the main burner, whereby the fuel can be cut 011' from the main burner without cutting off the other burners, substantially as specified.

11. The combination of the hot-water tank, the steanrgenerator, the vapor-burner, and pipes provided with valves, whereby the combastion of vapor and the generation of steam may be simultaneously controlled, substan-' WILLIAM EDGAR PRALL, JR.

\Vitnesses:

BENJ. R. CATLIN, FLORENCE DAVIES. 

